If the world is to stay within relatively safe global warming limits, one thing is certain: We can’t burn all the fossil fuels left available to us.
Several reports have shown that staying within a temperature increase of 2°C means burning only about one third of known reserves. Now a major new study shows exactly which reserves are climatically responsible and which ones aren’t.
The research, published in the journal Nature, comes from University College London and assumes that cheaper reserves would be exploited before more expensive ones. So a conventional oil deposit in, say, Texas, would be developed before an oil sands find in Alberta. The upshot is that a third of global oil reserves, half of gas reserves and 80% of coal reserves should remain in the ground, according to the analysis.
In the U.S., that means not burning 92% of coal resources, 4% of natural gas, and 6% of oil deposits. In the Middle East, it means 61% of proven gas and 38% of oil. And in the former Soviet Union, it means 94% of coal and 50% of gas.
So-called “unconventional” resources and expensive production methods comes off worst. The study finds little or no place for Arctic resources or Canadian tar sands, for instance. “We show that development of resources in the Arctic and any increase in unconventional oil production are incommensurate with efforts to limit average global warming to 2°C,” the paper says.
Another striking finding is that carbon sequestration (or CCS) makes little difference, despite the hopes and claims of the fossil fuel industry. That’s mainly because the authors assume the technology won’t be ready at scale before 2025 and that it will be expensive. For example, 75% of Canadian oil reserves are un-burnable without CCS, but only 74% are un-burnable with it–a meager 1% difference.
The research adds to a growing stack of “stranded assets” literature that’s starting to be noticed by investors. Governments, though, continue to encourage development of climatically unfeasible reserves, despite commitments to limit carbon emissions.
“Policy makers must realize that their instincts to completely use the fossil fuels within their countries are wholly incompatible with their commitments to the 2°C goal,” says lead author Christophe McGlade. “If they go ahead with developing their own resources, they must ask which resources elsewhere should remain unburnt in order for the carbon budget not to be exceeded.”